<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>slide</title>
    <link type="text/css" rel="stylesheet" href="css/slide.css"/>
    <script type="text/javascript" src="js/jquery.min.js"></script>
    <script type="text/javascript" src="js/slide.js"></script>
    <script type="text/javascript">
        $(function(){
            $('.btn .num').click(function(){
                var index = $(this).index();
                $('li img').each(function(){
                    $(this).css('zIndex','-1');
                });
                $('li img').eq(index).css('zIndex','0');
            });
        });
    </script>
</head>
<body>
<div class="slide" id="slide">
    <ul>
        <li class="imgs"><a href="#" target=""><img src="img/03.jpg" alt="img1" /></a></li>
        <li class="imgs">><a href="#" target=""><img src="img/02.jpg" alt="img2" /></a></li>
        <li class="imgs">><a href="#" target=""><img src="img/03.jpg" alt="img3" /></a></li>
    </ul>
    <div class="btn">
        <span class="num">1</span>
        <span class="num">2</span>
        <span class="num">3</span>
    </div>
    <div class='preNext pre'><</div><div class='preNext next'>></div>
</div>
</body>
</html>